Vikings WR Percy Harvin has been held out of practice for the past two days because of severe migraine headaches, according to a source with knowledge of the situation, and he is listed as questionable to play in Sunday’s home game against the 49ers.

This isn’t Harvin’s first bout with migraine headaches, although it isn’t known if they were related to him getting sick on the trip to a summertime minicamp, which he missed, and the NFL’s rookie symposium, from which he was sent home ill.

The first-round draft pick has gotten off to a solid start this season, catching two touchdown passes in the unbeaten Vikings’ first two games.

One day after calling his back injury “not a big deal,” Vikings RB Adrian Peterson practiced Friday, and is listed as probable to play against the 49ers. Vikings coach Brad Childress said Peterson “was a little bit limited,” as was LB E.J. Henderson, who’s listed as questionable with a shoulder injury.

• Injury reports for every team